Personally, I'd prefer to get a standard Raspberry Pi 4 model for any server-like duties. Get the 8GB RAM model and it's easy to run a lot of virtual machines on it for all of your different mini-server needs on a single device.

Managing a lot of different little Pis for different server-like things is fun for experimenting with clustering and multi-server management tools, but it gets old fast if you really just want several different VMs or containers.

VMWare ESXi is even available for the Raspberry Pi now: https://www.servethehome.com/getting-started-with-vmware-esx...